Danny's Corner

I've been wanting to make a motorized camera slider for a few years now. For one reason or another, this was as far as I got several years ago. A manual camera slider that didn't work too well. It was useful in teaching me how to do things in CAD, but that's about it.

For my new project to "make Danny not feel dumb" I figured I'd tackle this back burner project. It's been a bumpy ride, and there is a lot more to do, but DB1 is moving right along. But like I said, it's been a bumpy ride.

The first order of business was to mockup a new slider that would move on its own. A bit of CAD, printing, and rooting around my junk boxes resulted in this. Those new diode filters by cabristor really proved their worth with these prints.

With the mechanical prototype all assembled, I turned my attention to the electronics. And here's where the road started to get bumpy. I'm using Arduino Nano clones from China. They are rather odd, and I've been having a lot of problems identifying the pin ID numbers. Some pins work, some don't, some are mislabeled... Odd.

With a bit of patience and scanning code I cooked up, I was able to get my microswitches and a small I2C OLED display to work. I then started plugging away at the stepper driver wiring. But like I mentioned before, these Arduino's are odd. So, the stepper driver would just sit there doing nothing. In a moment of ignorance and carelessness, I connected 24v power to one of my rails...

Pop pop! Two electrolytic caps gave up. If that was all that died, I'd just chalk it up as a lesson learned. Unfortunately the lesson was continuing.

Not only did those two caps on the breadboard power input give up, the power from the 24v bus went across that breadboard power pcb and to the logic level voltage bus. Which then took out the stepper driver, the odd nano, and my USB3 hub. That's what happens when you inadvertently supply 24v power to logic level voltage. :( The OLED however, shrugged it right off. The USB hub I'm sure saved my laptop from harm too. So, it could have been worse. I also have lots of spares, of like, everything.

Lesson learned, or so I thought. Instead of continuing on with another spare clone arduino nano, I pulled out one of my genuine Uno's to figure out what the stepper driver wiring was giving me so much grief. Turns out, it was definitely me still not quite figuring out which pins worked or not on the nano, as everything worked just fine on the Uno. 12v lines were connected up to the driver and the darn thing started moving around under its own power. Sweet! But it was also buzzing like crazy. So, I swapped up to 24v to see if that was more what the stepper motor wanted.

Popped another cap. Ugh. For extra credit, I learned I should read the labels on things. I used a 16v 100mf cap to smooth out any input power spikes on the driver. At 12v, it's fine, maybe pushing it a little close to the cap specs depending on who you talk to, but it was fine and worked. Give it 24v however, and these 5yr old electrolytics pop right away.

Sigh...

Not sure I feel any smarter. The main wiring is all prototyped in though. So that's something. More to come on this. I need to write my Arduino sketch and bring it all together.